1. Field of the Invention
The invention relates to photo-optical switches and keyboards and more particularly to a flat planar monolithic photo-optical switch and keyboard apparatus.
2. Description of the Prior Art
Fiber optical keyboards and switches are of interest because they reduce the number of light emitting diodes (LED's) and detectors that may be required, unlike the one for one requirement of earlier photo-optical keyboards.
One LED can illuminate a bundle of fibers, each one of which goes to a separate key on the keyboard. At each key another fiber receives the transmitted light and conducts it to a photo-detector. If a key is depressed the light is blocked by the key stem or blade and the detector "sees" the loss of light as an operational signal. By multiplexing the LED's and detectors only one LED is required for each row and one detector for each column in a keyboard matrix.
A problem with the fiber optic keyboard is the present difficulty is fabricating and/or assembling all the fibers into a keyboard matrix array. It would be difficult to automate and the cost of assembly could conceivably out weigh the cost savings resulting from the reduced numbers of LED's and detectors.
It is an important object therefore of the present invention to solve these and other problems in a new, novel and heretofore unobvious manner.
Another object of the invention is to avoid the necessity or requirement for individual fiber strands or elements thus overcoming the assembly problems.
It is also an object of the invention to provide a one piece, molded, integrated optical assembly in the form of a keyboard matrix.